Is there a difference between a timeline and a universe as established by the MCU?

After watching the Loki series, my understanding is that a single reality/universe exists with the potential to branch at any point along its timeline. Nexus events are these branching points that the TVA dedicates itself to pruning.

The speech that He Who Remains gives near the end of the series has led me to believe that originally, the unpoliced timeline had several, if not infinite, branches and that several Kang variants duked it out for power. As the winner of the war, He Who Remains establishes the TVA to remove the possibility for other Kangs to exist.

By this understanding, "multiverse" and "multi-timeline" mean the same thing, referring to many branches in reality occurring at various points across the timeline.

A few quick pieces of evidence for this argument:

  • Only one Kang exists (He Who Remains).
  • The events in Loki appear to be the spark that leads to future movies like Doctor Strange in the Multiverse of Madness. If a multiverse already exists, the events of Loki seem irrelevant.
  • The TVA is obsessed with timeline variations. If universe variations exist, you'd think they would try to prune these as well, given that the whole point is preventing alternate Kangs.

However, I've seen it argued in other places (notably here and here, for example) that a timeline and a universe are 2 separate, distinct concepts meaning that a multiverse exists of entirely distinct realities that all follow the same loose series of events (the Sacred Timeline) and that the timeline splits talked about by He Who Remains and policed by the TVA are completely different from that multiverse.

A few quick evidences:

  • Alligator and female Lokis don't seem compatible with timeline variations alone.
  • The TVA allows minor timeline variations that don't cause a nexus event, the assumption being that these minor variations are multiverse splits.

Which is it?

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    I can see the point about alligators, but why could Loki never be born a woman?
    – Stef
    Commented Aug 4, 2021 at 13:39
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    @Stef - Certainly we can hypothesize a scenario where his sex is changed due to a timeline variation at conception where he's just born female from the get-go. Or maybe she's an entirely different frost giant that ends up growing up as an Asgardian instead of the "Loki" we know. But conventional logic would tell us that this variation alone would be their nexus event. Instead she's pruned later in her childhood leaving us to assume her nexus event was something else entirely. Commented Aug 4, 2021 at 14:20
  • 1
    @Stef - The reason it's included as evidence of a multiverse independent of what happens with the Sacred Timeline is because if one singular reality exists, pruned variants would most likely be so close to their "original" as to be indistinguishable outside of the one detail that got them pruned. On the other hand, these outrageously different variants could just be examples of the Rule of Cool and shouldn't be thought about too deeply. Commented Aug 4, 2021 at 14:26
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    We don't know that Loki being born an alligator is why he was pruned. What if he was cursed and turned into an alligator? Much like frog Thor in the comics. And I think a universe consists of time and space, so isn't a timeline that's taking up physical space a universe? Thus timelines = multiverse. That's just my thoughts about it.
    – Villan
    Commented Aug 4, 2021 at 16:59
  • 2
    @TheIronCheek: maybe, although again, "simultaneously" loses a fair bit of meaning once timelines and time travel are in the mix. Commented Aug 4, 2021 at 22:16

5 Answers 5


The Sacred Timeline apparently isn't a single timeline, but rather a bundle of timelines all flowing in the same general direction. See this answer to another question for a more detailed explanation, with relevant citations.

As for the main thrust of your question, I take the view that there's no fundamental difference between the "timelines" mentioned in the MCU, and parallel universes. There are a number of things that point to this being the case.

Firstly, within the Loki series, the "multiversal war" was presented as a war between different "timelines," and the existence of the multiverse itself linked to the branching of one timeline from another.

MISS MINUTES: Long ago, there was a vast multiversal war. Countless unique timelines battled each other for supremacy, nearly resulting in the total destruction of... well, everything. But then, the all-knowing Time-Keepers emerged, bringing peace by reorganizing the multiverse into a single timeline, the Sacred Timeline. Now, the Time-Keepers protect and preserve the proper flow of time for everyone and everything. But sometimes, people like you veer off the path the Time-Keepers created. We call those Variants. Maybe you started an uprising, or were just late for work. Whatever it was, stepping off your path created a nexus event, which, left unchecked, could branch off into madness, leading to another multiversal war.

Loki - S01E01 - "Glorious Purpose"

He Who Remains also stated that each of his variants lived in different "universes" stacked on top of one another, and used the words "universes" and "realities" interchangeably.

HE WHO REMAINS: Eons ago, before the TVA, a variant of myself lived on Earth in the 31st century. He was a scientist and he discovered that there were universes stacked on top of his own. At the same time, other versions of us were learning the same thing. Naturally, they made contact. And for a while, there was peace. Narcissistic, self-congratulatory peace. "I love your shoes." "I love your hair." "Oh, man, nice nose." "Thanks, man." Et cetera. They shared technology and knowledge. Using the best of their universes to improve the others. However... not every version of me was so... so pure of heart. To some of us, new worlds meant only one thing, new lands to be conquered. The peace between realities... erupted into all-out war, each variant fighting to preserve their universe and annihilate the others. This was almost the end... ladies and gentlemen, of everything and everyone.

SYLVIE: And then the Time-Keepers came along and saved us all.

HE WHO REMAINS: Amen. No. No. Nope, this is where we diverge from the dogma. That first variant encountered a creature created from all the tears in reality, capable of consuming time and space itself. A creature... you both know.

LOKI: Alioth.

HE WHO REMAINS: Bingo! I harnessed the beast's power and began experimenting on it. I weaponized Alioth and I ended... I ended the Multiversal War. Once I isolated our timeline, all I had to do was manage the flow of time and prevent any further branches. Hence, the TVA. Hence, the Time-Keepers and a highly efficient bureaucracy. Hence, ages... and ages of cosmic harmony. Hence... you're welcome.

Loki - S01E06 - "For All Time. Always."

Secondly, in Avengers: Endgame, the Ancient One used the word "realities" when distinguishing between different timelines, and Banner used the words "timeline" and "reality" interchangeably.

THE ANCIENT ONE: I'm sorry, I can't help you, Bruce. If I give up the Time Stone to help your Reality, I'm dooming my own.

BRUCE BANNER: With all due respect, I'm not sure the science really supports that.

THE ANCIENT ONE: The Infinity Stones create what you experience as the flow of time. Remove one stone and that flow splits. Now, this may benefit your reality, but my new one... not so much. In this new branched Reality, without our chief weapon against the forces of darkness, our world will be overrun. Millions will suffer. So, tell me, Doctor, can your science prevent all that?

BRUCE BANNER: No, but we can erase it. Because once we are done with the stones, we can return each one to its own timeline at the moment it was taken. So, chronologically, in that reality, it never left.

Avengers: Endgame

Thirdly, in an interview with ScreenCrush, the head writer of the Loki series, Michael Waldron, used the words "universes" and "timelines" interchangeably.

SCREENCRUSH: Okay, understood. So my question is if there is the one “Sacred Timeline” of the Marvel Universe that the TVA has been protecting for some significant stretch of time, then how can there also be so many alternate timelines and variants as well?

MICHAEL WALDRON: Okay, The best I can explain it is our approach with time travel was the philosophy basically that time is always happening. So there are infinite instances of time always occurring at once. So you and I are having this conversation right now. There’s another instance of us having this conversation 10 seconds ago. There’s another instance of time of us having this conversation 10 seconds in the future. Generally, those three instances — you could literally say they’re all different universes in a way different timelines — are all the same. There are minute little fluctuations in each instance of time. So in you and I’s conversation, five times out of ten, I pick up and I say, “Hello.” And four times out of ten, I say, “Hey, nice to meet you.” And then maybe one time out of ten, I’d say, “Hey man, f— you. I don’t want to do this interview.”

Creator Michael Waldron Answers All Our Questions About ‘Loki’ And ‘Heels’

Fourthly, in the first episode of the What If...? series, the Watcher stated that Peggy Carter's decision to stay in the room where Steve Rogers was supposed to be injected with Dr. Erskine's serum -- rather than head up to the booth, like she did in Captain America: The First Avenger -- created a new "universe."

THE WATCHER: Time. Space. Reality. It's more than a linear path. It's a prism of endless possibility, where a single choice can branch out into infinite realities, creating alternate worlds from the ones you know. I am the Watcher. I am your guide through these vast new realities. Follow me and ponder the question... "What if...?"

THE WATCHER: Earth, June, 1943. The Nazi army marches across Europe, leaving death and destruction. The Allied armies band together to create a new kind of soldier. A Super Soldier. At humanity's darkest hour, a skinny kid from Brooklyn became Captain America. After turning the tide of World War II, he made the ultimate sacrifice, restoring peace and saving this universe. But in another universe, a single choice created a whole new hero.

STEVE ROGERS: All this to make one Super Soldier.

PEGGY CARTER: Paris has fallen. London might be next. If this works, you could end the war. We mere mortals can only dream of doing such things.

DR. ABRAHAM ERSKINE: Agent Carter, wouldn't you be more comfortable in the booth?

PEGGY CARTER: No, I'd prefer to stay.

THE WATCHER: There. That's the moment that created a new universe. When asked to leave the room, Margaret "Peggy" Carter chose to stay. But soon it would be her venturing into the unknown and creating a new world.

What If...? - S01E01 - "What If... Captain Carter Were The First Avenger?"

I believe there is an important distinction to be made between the terms "timeline" and "universe" when discussing certain other franchises, such as Back to the Future. In that story, there are multiple versions of the timeline, but as far as we're shown, these versions don't exist simultaneously in parallel. Rather, there's only ever a single timeline and universe, the history of which is rewritten each time a change is made in the past.

Within the MCU though, where multiple timelines can clearly exist simultaneously in parallel -- each with their own version of Earth and other planets and stars -- the distinction between a "timeline" and a "universe" ceases to hold any practical significance that I can see.

  • 1
    It's purely personal but I suspect in science fiction like star trek or doctor who where time is more fluid it lends itself to timeline rather than universe. The MCU is completely fixed and uses parallel universes with phase shifted time per the interview - meaning a nearly the same universe 10 seconds behind. Which occurs plenty in science fiction as well. Commented Aug 5, 2021 at 1:38
  • Check the episode numbers you mentioned after each quote, they're all wrong.
    – Shreedhar
    Commented Aug 5, 2021 at 11:02
  • I like this answer but I struggle with the existence of Loki variants so radically different from him that their mere existence should've been an nexus event. How do you reconcile this? Commented Aug 6, 2021 at 13:36
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    You might want to update this answer as of What If...? episode 4 where two timelines run in parallel in one universe. I will say though that normally your answer is correct and the two are used interchangeably.
    – TheLethalCarrot
    Commented Sep 10, 2021 at 11:05
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    I'll point out that it's entirely possible that the events depicted in What If? may take place "after" the events in the final episode of Loki season 1.
    – nick012000
    Commented Sep 17, 2021 at 5:03

It sure can be confusing! Thankfully, episode 4 of What If...? lays it all out very clearly, in a really easy-to-understand way that anyone can quickly and intuitively grasp without provoking any further questions.

Ha ha, just kidding.

However, we do see some stuff that suggests multiple timelines can exist within one universe. Spoilers ahead for What If... Doctor Strange Lost His Heart Instead of His Hands?

  1. In the universe portrayed in the episode, Doctor Strange repeatedly uses the Time Stone to travel back in time, in an attempt to change one event. This may or may not be an example of multiple timelines being created within one universe. (When skimming the Time Stone EULA, Strange sees the phrase "manipulation and alteration of timelines".)

  2. The event that Strange is trying to change is described by the Ancient One as an "absolute point in time", a brand-new concept that the MCU totally just invented all by itself. The Ancient One warns that changing absolute points in time is likely impossible, but if achieved could destroy the universe.

  3. The Ancient One also uses energy from the Dark Dimension* to split Doctor Strange into two separate beings, living in two timelines within one universe — exceedingly dangerous, apparently. The Strange in one timeline travels to the past and lives for centuries absorbing the power of other beings, until the fabric of this universe starts to break down.

  4. Doctor Strange eventually disproves the Ancient One's first assertion by reversing the absolute point in time. Unfortunately, the second assertion turns out to be bang on, and we see this universe reduced to nothing but a tiny purple geodesic dome.

This all seems like reasonable support for the idea that timelines can and do exist within a single universe, which exists within the Multiverse, observed by our buddy Belize Felix Bernard the Watcher. The absolute point in time that Strange was trying to change didn't occur in the Marvel Cinematic Universe we've watched for all these years, so apparently it's only absolute within the universe we were watching this week.

But Loki tho

How this ties in with the timelines and/or universes in Loki is not entirely clear. The description offered by He Who Remains, of multiple different universes stacked on top of one another, with different versions of beings in each, sure sounds like the multiverse we're getting to see more of in What If...?.

However, it's possible that these "universes" are in fact just timelines created within the Marvel Cinematic Universe we're familiar with, and that other universes do, or don't, have their own version of the "multiversal" timeline wars that He Who Remains describes to Loki and Sylvie. He Who Remains may only have discovered timelines within his own universe, and not the other universes that the Watcher apparently enjoys browsing through.

So... all clear? If not, try saying "prism of endless possibility" until you don't care any more, or your Disney Plus subscription expires.

* Don't get distracted!

  • I'll point out that it seems like "absolute point in time" might be another term for what the TVA calls a "Nexus Event" - especially since undoing it undoes the variant universe.
    – nick012000
    Commented Sep 17, 2021 at 5:05
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    @nick012000 I’m not sure that makes sense. As I understood the term “nexus event” in Loki, it referred to an event that caused a timeline split — i.e. one outcome on one timeline, another outcome on another. (And possibly limited to just the timeline splits that the TVA wanted to prevent.) Whereas an absolute point in time seems like it’s a single outcome that’s always guaranteed to happen, unless enormous magical power reverses it and also causes that universe to collapse into a tiny purple geodesic dome. Commented Sep 17, 2021 at 10:30
  • Except that we know it wasn't actually "always guaranteed to happen", because it didn't happen in the original "sacred" timeline. It was just always guaranteed to happen in the branching timeline - presumably due to the fact that it was what caused that timeline to branch off of the original timeline, so preventing it from happening would also prevent that branch from occurring - and when it was undone, the branch was purged, similarly to how the TVA purges branches by deleting their Nexus Events.
    – nick012000
    Commented Sep 17, 2021 at 13:24
  • @nick012000: such certainty you have about timelines and universes! The entire premise of my answer is that timelines branch within universes. In the What If...? episode, we apparently saw Strange Supreme travel between many timelines trying to save Christine, and Strange Classic living in his own timeline while Strange Supreme ate all those creatures. But all that timeline monkeying caused that universe to end, not the entire multiverse (cos, y'know, we have more episodes and stuff). I'm not sure how that makes sense unless timelines are a thing contained within a universe. Commented Sep 17, 2021 at 13:33
  • But of course, I could be totally wrong about all this. We don't yet really know how variant timelines from Loki, or different universes from What If...?, are created. Maybe the Watcher and He Who Remains are peers, and the universes we see in What If...? are totally like the timelines we glimpse in Loki. Commented Sep 17, 2021 at 13:38

They may be used interchangeably, but there is still a difference as shown in Doctor Strange.

Mordo: Dormammu dwells in the Dark Dimension, beyond time. He is the cosmic conquerer, the destroyer of worlds. A being of infinite power and endless hunger, on a quest to invade every universe and bring all worlds into his Dark Dimension.

Note that some of these universes, such as the Dark Dimension, are not simply different timelines as the nature of the timeless nature of the Dark Dimension and Dormammu demonstrates. During her introduction of Strange to magic, the Ancient One took him on a metaphysical journey through several different realities.

  • 4
    It's been a while since I've watched Doctor Strange but I'm not convinced that these dimensions are the same as an alternate universe. I see the Dark Dimension in the same way I see the location of TVA headquarters: a realm outside time existing in the same universe as Earth/Space/Asgard. But maybe a rewatch will change my mind. Commented Aug 4, 2021 at 21:08
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    @Keith Morrison - How do we know that the Dark Dimension actually qualifies as a universe? Has it ever been described as such within the MCU? Commented Aug 4, 2021 at 21:29
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    @LogicDictates: let's not get into all that again. Commented Aug 4, 2021 at 21:43
  • @TheIronCheek personally I'm regarding the TVA location with the window view of the multiverse as probably the largest thing we can consider our universe before it starts getting weird. Commented Aug 5, 2021 at 1:31
  • There is a beyond realm, that is outside our universe and a quantum universe that is within our own and potentially other or every universe. I think Realms are different, but dimensions not so much. A dimension is like a closet within a universe.
    – Villan
    Commented Aug 5, 2021 at 14:56

In the MCU, the multiverse is ONLY a collection of timelines defined by a single set of physics, but this is not necessarily true outside of the MCU

The idea of a multiverse comes from String Theory which defines the multiverse as any theoretical reality based on the existence of multiple realities. What the MCU calls a multiverse is based more-or-less on the many-worlds interpretation of quantum mechanics*. It is what science calls a "quantum multiverse" where the multiverse is a collection of many realities defined by divergent time-lines, but this is only ONE kind of multiverse.

There is also the concept of the "Ultimate Multiverse" which is much grander and allows for all possible variant timelines using every possible variable system of physics that could exist. The MCU calls this the Omniverse which would include places like the Dark Dimension where the basic rules of science as we know them cease to exist. In the MCU, the Omniverse is a collection of Multiverses; so, leaving your own system of physics would constitute leaving your Multiverse.

*As lucasbachmann points out in comments, Marvel does not exactly represent science... ever... I only bring up the idea of the quantum multiverse to define the scale of the Marvel Multiverse, not its exact behaviors.

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    I'll respectfully disagree with "What the MCU calls a multiverse is based specifically on the many-worlds interpretation of quantum mechanics." The other universes of the MCU appear to derive exclusively from two fundamental rules. 1. Time travel is possible at the quantum realm size level. (And occurs naturally) 2. Time travel creates a parallel universe to prevent paradoxes from affecting the original universe. This is NOT the interpretation of QM which solves the superposition collapse measurement problem with basically all possibilities happened in different universes. Commented Aug 5, 2021 at 0:29
  • "The MCU calls this the Omniverse" — does it? When? Commented Aug 17, 2021 at 10:36
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    @PaulD.Waite It is clear that not every Marvel writer is aware of the distinction, so there may be some inconsistencies, but it is defined in the Official Handbook of the Marvel Universe: Alternate Universes. That said, the ignorance of characters in the stories of the difference can easily handwave away the lack of attention to canon since few marvel characters would know there is something beyond the multiverse. marvel.fandom.com/wiki/Category:Omniverse/Mentions <- here is a list of 10 publications that mention the Omniverse.
    – Nosajimiki
    Commented Aug 17, 2021 at 16:44
  • Some authors have used Hyperverse, to mean what is beyond the multiverse, but Marvel has officially said that this is not canon.
    – Nosajimiki
    Commented Aug 17, 2021 at 16:45
  • This answer is too poorly sourced to upvote but even if it wasn't, it doesn't appear to even answer my original question. Commented Aug 17, 2021 at 18:51

From what I understand, timeline and universe are different concepts. Alternate universe is another copy of the space. Alternate timeline is another copy of time.

If hypothetically, we assume that universe and timeline are same concepts and can be used interchangeably, then, how do you explain completely different versions of Loki like alligator Loki, boastful Loki, female Loki? If universe and timelines are same concept, then it means two out of three spidermen are variants. Why didn’t TVA prune two spidermen and why do they look so different?

According to me, there are multiple copies of space which translates into multiple universes. In each universe, there could be a different Loki. Good Loki, bad Loki, male Loki, female Loki, alligator Loki. And all universes travel through their own sacred timelines. But a nexus event can generate a new timeline within the universe bringing about completely different outcome. So Toby, Andrew and Tom are not variants of alternate timelines. They are different spidermen of different universes. They were not variants, hence didn’t get pruned.

Similarly, Loki, female loki, alligator loki, boastful loki belong to different universes. But loki during his childhood, killed Thor once, so that version of him got pruned. Another time loki created an alternate timeline during New York war, hence got pruned again.

Female loki, alligator loki and boastful loki weren’t pruned simply because they are alternate versions of loki. They were pruned because they probably created a nexus event within their own universe.

  • 1
    Hi, welcome to SF&F. I think this would be better if you gave some references/examples; it seems to me that some of the "universes" are not simple copies, they are actually radically different. It's also not clear what you mean by a "copy of time."
    – DavidW
    Commented Apr 26, 2022 at 22:46

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